1. Field of the Invention
This invention relates to a sheet counter system, e.g., a sheet counter or a sheet discriminating counter, etc., i.e., a system for carrying out counting processing of bills, checks or slips, etc.
2. Description of the Prior Art
A conventional sheet counter system generally has a feeding part for feeding out, one by one, sheets or the like stacked within a hopper section; a carrying part for carrying the sheets or the like fed out by the feeding part; a counting part for counting the sheets or the like carried by the carrying part; and a stacking part for stacking the sheets or the like counted by the counting part.
The essential part of one example of such conventional sheet counter system will now be described with reference to FIGS. 15A and 15B.
In these figures, a kicker roller 32, feed rollers 33 (see FIG. 15B) at opposite ends of a rotary shaft 41, and a gate roller 34 constitute feeding (drawing) means for feeding out sheets or the like stacked or accumulated within a hopper section 31. Practically, two kicker rollers 32 are provided along their common axis, however, the explanation will be made with reference to only one kicker roller. Respective components of this feeding means are driven by a drive motor (not shown).
Furthermore, a feed roller 33' at a central position between rollers 33, a roller 35 opposite to the feed roller 33' and acceleration rollers 36, 37 constitute carrying (transfer) means for carrying (transferring) sheets or the like fed out by the feeding means. Such acceleration rollers 36, 37 are also driven by the above-described drive motor. The sheets or the like which have been fed out by the above-described feeding means are carried (transferred) along a carrier (transferring) path formed by guide plates 39a, 39b. In this example, the acceleration roller 36 is caused to have large inertia. Thus, acceleration rollers 36, 37 are driven by inertia even after the drive motor is stopped so that they carry or transfer sheets or the like.
A stacker 40 and a stacker fan 38, practically two coaxial stacker fans, constitute stacking means. Stacker fan 38 stacks sheets or the like carried by the carrying means into stacker 40. Stacker fan 38 is driven by an independent motor.
A light emitting element S and a light receiving element S' detect sheets or the like and constitute counting means for counting the number of sheets or the like carried by the above-described carrying means.
One processing mode known to be carried out by sheet counter systems of this kind is counting batch processing. This counting batch processing is a mode adapted so that when a predetermined number (hereinafter referred to as "a batch number") of sheets or the like are stacked within the stacker 40, the feeding means and/or the carrying means are once stopped. In accordance with this processing mode, sheets or the like within the stacker 40 are taken out every time the feeding means or the carrying means is stopped. Thereafter, such means is restarted, thereby making it possible to sort a batch number for a second time sheets or the like which have been subjected to counting processing.
For example, when it is assumed that the batch number is "100", the feeding means is stopped at the point in time when the hundredth sheet or the like is fed out from the hopper section 31, so the one hundred first sheet and sheets succeeding thereto are not fed out from the hopper section 31. When the hundredth sheet or the like is carried or transferred up to the stacker fan 38, the carrying means is stopped.
A deceleration (braking) method when the feeding means is caused to be stopped is shown in FIG. 16. In this figure, the ordinate is a feeding speed (number of sheets/minute) and the abscissa is an elapsed time t. As stated above, in the conventional sheet counter system, when the final sheet (the hundredth sheet in this example) or the like before stopping is detected by the light receiving element S' of the counting means, the drive motor of the feeding means is braked. Thereafter, the feeding speed gradually lowers and becomes equal to zero after completion of the feeding operation.
In such conventional sheet counter system, it is required that the counter system be compact.
However, in the case where such a system is made compact, the spacings between respective rollers 32-37 are shortened. Accordingly, in the case where the drive motor is braked at a timing as shown in FIG. 16, there is the possibility that when the length in a carrying direction of the sheet or the like is long, the drive motor may be stopped with the trailing end of the sheet or the like being between roller pair 33, 34 (see FIGS. 15A and 15B), or remaining within the hopper section 31, so that such sheet or the like fails to be stacked within the stacker 40.
On the contrary, there is employed a method as shown in FIG. 17 to conduct carrying (transfer) for a predetermined distance (40 mm in this example) after the front end of the sheet or the like is detected by the counting means S, S' and thereafter to brake the drive motor, thereby making it possible to eliminate the above-mentioned drawback. Namely, in accordance with this method, even in the case where sheets or the like are long, they can be securely stacked within the stacker 40.
However, when control of the brake of the drive motor is carried out by such timing to retard or delay the timing at which the drive motor is stopped, in the case where sheets or the like are short, opposite to the above, there occurs a new drawback such that when the final (hundredth) sheet or the like before stopping reaches the stacker fan 38, the next (one hundred first) sheet or the like may be fed out from the rollers 33, 34.
Namely, the time period from the time when the one hundredth sheet or the like is carried or transferred from the hopper section 31 and the one hundred first sheet or the like comes into contact with the kicker roller 32, the feed rollers 33 and the gate roller 34 until these rollers are stopped becomes longer as the length of the sheet or the like becomes shorter. Such condition in which a part of the one hundred first sheet protrudes into the transferring path from the feed roller 33 and the gate roller 34 when the hundredth sheet is transferred and the feeding of next sheet is stopped is defined as "excessive feeding".
Since such excessive feeding of the sheet or the like takes place in response to a contact as described above, as the length of the sheet or the like becomes shorter (i.e., the contact time becomes longer), the extend of excessive feeding becomes greater.
Accordingly, when the extend of excessive feeding of the one hundred first sheet or the like becomes greater as described above, the possibility that such sheet or the like may be damaged in taking out the sheet or the like from between rollers 33 and 34 by a user or an operator becomes higher. Even if such sheet or the like can be taken out in such a manner that it is not damaged, there results increased labor for a user. For example, when the number of sheets or the like stacked in advance within the hopper section 31 is one hundred ten (110), and one hundred (100) sheets or the like are stacked within the stacker 40 and the remaining ten (10) sheets or the like are taken out from the hopper section, such problem would occur.
Furthermore, in such a case that a sheet detection sensor is provided in proximity of the kicker roller 32 at the hopper section 31 to detect whether or not there are remaining sheets or the like, inconveniences as described below also take place.
(1) There are instances where, when one hundred and one sheets or the like are stacked in the hopper 31 and the one hundred first sheet is excessively fed out, if the extent of excessive feeding is large, then the trailing end of that sheet or the like is passed through the sheet detection sensor position, so it will be judged that there is no sheet or the like within the hopper section 31, even though the one hundred and first sheet or the like is left therein.
(2) Even in the case where, when the number of sheets or the like stacked in advance within the hopper section 31 is one hundred ten (110), and one hundred (100) sheets or the like are fed and stacked in the stacker 40 and the remaining ten (10) sheets or the like are taken out from the hopper section, an operator may forget to remove the one hundred first sheet or the like which has been excessively fed out. Thus, it may be judged that no sheet or the like is left within the hopper section 31 in spite of the one hundred and first sheet or the like being left within the hopper section 31.
(3) In the case where there remains one sheet or the like which has been excessively fed out in this way and counting processing is performed, remaining sheets and the like are also counting processed. As a result, the counted number of sheets or the like and the counted number of sheets or the like stacked within the hopper section 31 are not in correspondence with each other, thus constituting an error in the overall operation.
On the other hand, in a conventional sheet counter system as described above, it is also required to improve the processing speed.
When it is now assumed that the carrying speed of the sheet or the like is caused to be high in order to improve the processing speed, in the case where the drive motor is braked after the final sheet or the like before stopping is detected by the light receiving element S' as shown in FIG. 16, the stop timing of the drive motor is delayed, so the next sheet or the like would be fed out. Accordingly, also in this case, drawbacks as in the above-mentioned items (1)-(3) take place.
On the contrary, in order to eliminate such drawback, the present inventors tried a method in which when a sheet (the ninety sixth sheet in this example) or the like preceding by a fixed number of sheets relative to the final sheet before stopping is detected by the light receiving element S', the feeding speed is caused to be reduced, and the drive motor is braked after the final (hundredth) sheet or the like is detected by the light receiving element S'.
With such method, however, feeding speeds at the point in time when the hundredth sheet or the like is detected by the light receiving element S' would become diverse, thus failing to precisely control the stop timing. For example, when the stop timing is caused to be earlier than a set value, the carrying means is stopped before the hundredth sheet or the like reaches the stacker fan 38, and such sheet will be left within the carrying path.
For this reason, the present inventors tried a method in-which a feeding speed at the point in time when the hundredth sheet or the like is detected by the light receiving element S' is measured, whereby when the measured speed is less than a reference speed, the sheet or the like is further carried or transferred by a predetermined distance thereafter to brake the drive motor.
With such method, in the case where the length of the sheet or the like is long, a satisfactory result was provided. In contrast, in the case where the length of the sheet is short, the one hundred first sheet or the like was fed out. Accordingly, also in this case, drawbacks as in the above-described items (1)-(3) may take place.